In this study, we investigate the possibility of enhancing the di-jet resonance searches by tagging the final state radiation (FSR) jet using an event-level deep neural network. It is found that solely relying on the 4-momenta of the leading three jets allows the algorithm to achieve good discriminating power that can identify the hardest FSR jet in the signal while rejecting other soft jets. Once the invariant mass is corrected with the tagged FSR jet, the mass resolution of the signal is greatly enhanced, and the sensitivity of the search is also improved by more than 10%. By crafting the input variables carefully, the algorithm introduces minimal mass sculpting for the background, and its applicability extends to a broad mass range. This work proves that FSR jet tagging can potentially enhance di-jet resonance searches, suiting various stages of the physics programmes at the Large Hadron Collider (LHC) and High-Luminosity LHC (HL-LHC).

China

Bingxuan Liu

Yuxuan Shen

Yuanshunzi Sui

Enhancing di-jet resonance searches via a final-state radiation jet tagging algorithm * Bingxuan Liu is supported by Shenzhen Campus of the Sun Yat-sen University under project 74140-12255011, and by the Young Scientists Fund (C Class) of the National Natural Science Foundation of China (12405122). Both Yuxuan Shen and Yuanshunzi Sui are supported by College Students’ Innovative Entrepreneurial Training Plan Program

Radon and its progeny constitute a major source of background in rare-event physics experiments, such as those searching for dark matter, neutrinos, and neutrinoless double <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>β</mi></math> decay, due to their origin as unavoidable decay products of natural uranium. In particular, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Rn</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>222</mn></mrow></mmultiscripts></mrow></math> and its long-lived daughter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Pb</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>210</mn></mrow></mmultiscripts></mrow></math> can diffuse from detector material surfaces, resulting in sustained background contributions. To investigate this process, a system was developed using a controlled radon source, a vacuum chamber with a high electric field, and a thin nylon-6 film to enable deposition of radon progeny onto the film surface. Nylon-6 was selected for the initial measurement given its history in low-background experiments. We intend to systematically study diffusion in various polymers in the future. Our setup allowed for controlled study of the diffusion behavior of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Pb</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>210</mn></mrow></mmultiscripts></mrow></math> and its daughter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Po</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>210</mn></mrow></mmultiscripts></mrow></math> under varying humidity conditions. Our results show that both <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Pb</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>210</mn></mrow></mmultiscripts></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Po</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>210</mn></mrow></mmultiscripts></mrow></math> diffuse significantly in nylon under high relative humidity, which can potentially lead to internal contamination and increased background in low-background detectors. The diffusivity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Pb</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>210</mn></mrow></mmultiscripts></mrow></math> was found to be lower than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1.14</mn><mo>×</mo><mrow><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>15</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>cm</mi></mrow><mn>2</mn></msup><mo>/</mo><mi mathvariant="normal">s</mi></mrow></math> at 40% relative humidity (RH) and to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>4.03</mn><mo>±</mo><mn>1.01</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>13</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>cm</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>/</mo><mi mathvariant="normal">s</mi></mrow></math> at 95% RH. The diffusivity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Po</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>210</mn></mrow></mmultiscripts></mrow></math> at 95% RH was measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>3.94</mn><mo>±</mo><mn>0.98</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>13</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>cm</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>/</mo><mi mathvariant="normal">s</mi></mrow></math>. These findings underscore the importance of controlling environmental humidity and material exposure to radon in the design of ultralow-background experiments.

P. Adhikari

M.G. Boulay

R. Crampton

M. Perry

D. Sinclair

Diffusion of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Pb</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>210</mn></mrow></mmultiscripts></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Po</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>210</mn></mrow></mmultiscripts></mrow></math> in nylon

RHIC and LHC have injected <math altimg='si2.svg'><mrow><msup><mrow /><mn>16</mn></msup><mrow><mi mathvariant='normal'>O</mi></mrow></mrow></math> nuclei in their accelerator complexes with a focus on investigating collectivity and the origin of quark-gluon plasma signatures in small collision systems. The <math altimg='si2.svg'><mrow><msup><mrow /><mn>16</mn></msup><mrow><mi mathvariant='normal'>O</mi></mrow></mrow></math> nuclei are known to possess clusters of <math altimg='si1.svg'><mi>&#945;</mi></math>-particles ( <math altimg='si19.svg'><mrow><msup><mrow /><mn>4</mn></msup><mrow><mi mathvariant='normal'>H</mi></mrow><mi>e</mi></mrow></math>) inside the nucleus. This paper attempts to study the clustered-nuclear-geometry dependence of anisotropic flow coefficients such as elliptic flow ( <math altimg='si20.svg'><msub><mi>v</mi><mn>2</mn></msub></math>) and triangular flow ( <math altimg='si21.svg'><msub><mi>v</mi><mn>3</mn></msub></math>), which are sensitive to the nuclear geometry of colliding nuclei. The study is performed in pO and OO collisions at <math altimg='si6.svg'><mrow><msqrt><msub><mi>s</mi><mrow><mrow><mi mathvariant='normal'>N</mi></mrow><mi>N</mi></mrow></msub></msqrt><mo linebreak='goodbreak'>=</mo><mn>9.61</mn></mrow></math> TeV and 7 TeV respectively, employing a hybrid model encompassing IP-Glasma + MUSIC + iSS + UrQMD. The results of the clustered nuclear geometry are compared with those of the Woods&#8211;Saxon nuclear profile. Both initial and final state anisotropies are estimated. This study is thus one of its first kind, where the study of anisotropic flow coefficients for pO and OO collisions is presented using a hybrid hydrodynamics model. While the effect of <math altimg='si1.svg'><mi>&#945;</mi></math>-clustering in pO is found to be small, it is significant for each observable studied in OO collisions. It is also observed that the magnitude of this effect has a noteworthy dependence on the size of the 4He.

India

Hungary

Aswathy Menon Kavumpadikkal Radhakrishnan

Suraj Prasad

Finland

Neelkamal Mallick

Raghunath Sahoo

Gergely Gábor Barnaföldi

Probing the sensitivity of anisotropic flow coefficients to the initial nuclear structure in pO and OO collisions at the LHC

Symmetries and their anomalies are powerful tools for understanding quantum systems. However, realistic systems are often subject to disorders, dissipation and decoherence. In many circumstances, symmetries are not exact but only on average. This work investigates the constraints on mixed states resulting from non-commuting average symmetries. We will focus on the cases where the commutation relations of the average symmetry generators are violated by nontrivial phases, and call such average symmetry anomalous. We show that anomalous average symmetry implies degeneracy in the density matrix eigenvalues, and present several lattice examples with average symmetries, including XY chain, Heisenberg chain, and deformed toric code models. In certain cases, the results can be further extended to reduced density matrices, leading to a new lower bound on the entanglement entropy. We discuss several applications in the contexts of many body localization, quantum channels, entanglement phase transitions and also derive new constraints on the Lindbladian evolution of open quantum systems.

United States

Po-Shen Hsin

Zhu-Xi Luo

Hao-Yu Sun

Anomalies of average symmetries: entanglement and open quantum systems

Anomalies of global symmetry provide powerful tool to constrain the dynamics of quantum systems, such as anomaly matching in the renormalization group flow and obstruction to symmetric mass generation. In this note we compute the anomalies in 2+1d time-reversal symmetric gauge theories with massless fermions in the fundamental and rank-two tensor representations, where the gauge groups are SU(N), SO(N), Sp(N), U(1). The fermion parity is part of the gauge group and the theories are bosonic. The time-reversal symmetry satisfies T 2 = 1 or T 2 = <math> <mi>M</mi> </math> $$ \mathcal{M} $$ where <math> <mi>M</mi> </math> $$ \mathcal{M} $$ is an internal magnetic symmetry. We show that some of the bosonic gauge theories have time-reversal anomaly with c − ≠ 0 mod 8 that is absent in fermionic systems. The anomalies of the gauge theories can be nontrivial even when the number of Majorana fermions is a multiple of 16 and ν = 0.

United Kingdom

Time-reversal anomalies of QCD3 and QED3

The nucleus 212Po has been produced through the fragmentation of a 238U primary beam at 1 GeV/nucleon at GSI, separated with the FRagment Separator, FRS, and studied via isomer <italic>&#947;</italic>-decay spectroscopy with the RISING setup. Two delayed previously unknown <italic>&#947;</italic> rays have been observed. One has been attributed to the E3 decay of a 21 &#8722; isomeric state feeding the <italic>&#945;</italic>-emitting 45-s (18 +) high-spin isomer. The other <italic>&#947;</italic>-ray line has been assigned to the decay of a higher-lying 23 + metastable state. These are the first observations of high-spin states above the 212Po (18 +) isomer, by virtue of the selectivity obtained via ion-by-ion identification of 238U fragmentation products. Comparison with shell-model calculations points to shortfalls in the nuclear interactions involving high- <italic>j</italic> proton and neutron orbitals, to which the region around <italic>Z</italic>&#8764;100 is sensitive.

Italy

L. Zago

A. Gottardo

J.J. Valiente-Dobón

G. Benzoni

Spain

A. Gadea

Germany

M. Górska

S. Lunardi

Zs. Podolyák

P.H. Regan

Sweden

D. Rudolph

A. Algora

G. de Angelis

D. Bazzacco

J. Benlliure

P. Boutachkov

A. Bracco

A.M. Bruce

F. Camera

E. Casarejos

M.L. Cortés

F.C.L. Crespi

A. Corsi

C. Domingo-Pardo

M. Doncel

T. Engert

H. Geissel

J. Gerl

A. Goasduff

N. Goel

Poland

J. Grebosz

E. Gregor

T. Habermann

S. Klupp

I. Kojouharov

N. Kurz

S.M. Lenzi

S. Leoni

S. Mandal

R. Menegazzo

D. Mengoni

B. Million

A.I. Morales

D.R. Napoli

F. Naqvi

C. Nociforo

M. Pfützner

S. Pietri

A. Prochazka

F. Recchia

E. Sahin

H. Schaffner

A. Sharma

Slovakia

B. Sitar

D. Siwal

P. Strmen

I. Szarka

C.A. Ur

P.M. Walker

H. Weick

O. Wieland

H.J. Wollersheim

High-spin states in 212Po above the <italic>&#945;</italic>-decaying (18 +) isomer

This work investigates the gapped interfaces of 3+1d fracton phases of matter using foliated gauge theories and lattice models. We analyze the gapped boundaries and gapped interfaces in X cube model, and the gapped interfaces between the X-cube model and the toric code. The gapped interfaces are either “undecorated” or “decorated”, where the “decorated” interfaces have additional Chern-Simons like actions for foliated gauge fields. We discover many new gapped boundaries and interfaces, such as (1) a gapped boundary for X-cube model where the electric lineons orthogonal to the interface become the magnetic lineons, the latter are the composite of magnetic planons; (2) a Kramers-Wannier-duality type gapped interface between the X-cube model and the toric code model from gauging planar subsystem one-form symmetry; and (3) an electromagnetic duality interface in the X-cube model that exchanges the electric and magnetic lineons.

Ananth Malladi

Gapped interfaces in fracton models and foliated fields

For any quantum system invariant under gauging a higher-form global symmetry, we construct a noninvertible topological defect by gauging in only half of the spacetime. This generalizes the Kramers-Wannier duality line in <math><mrow><mn>1</mn><mo>+</mo><mn>1</mn></mrow></math> dimensions to higher spacetime dimensions. We focus on the case of a one-form symmetry in <math><mrow><mn>3</mn><mo>+</mo><mn>1</mn></mrow></math> dimensions, and determine the fusion rule. From a direct analysis of one-form symmetry protected topological phases, we show that the existence of certain kinds of duality defects is intrinsically incompatible with a trivially gapped phase. We give an explicit realization of this duality defect in the free Maxwell theory, both in the continuum and in a modified Villain lattice model. The duality defect is realized by a Chern-Simons coupling between the gauge fields from the two sides. We further construct the duality defect in non-Abelian gauge theories and the <math><msub><mi>Z</mi><mi>N</mi></msub></math> lattice gauge theory.

Yichul Choi

Clay Córdova

Ho Tat Lam

Shu-Heng Shao

Noninvertible duality defects in <math><mrow><mn>3</mn><mo>+</mo><mn>1</mn></mrow></math> dimensions

Rare event physics demands very detailed background control, high-performance detectors, and custom analysis strategies. Cryogenic calorimeters combine all these ingredients very effectively, representing a promising tool for next-generation experiments. CUPID-0 is one of the most advanced examples of such a technique, having demonstrated its potential with several results obtained with limited exposure. In this paper, we present a further application. Exploiting the analysis of delayed coincidence, we can identify the signals caused by the $^{220}$Rn-$^{216}$Po decay sequence on an event-by-event basis. The analysis of these events allows us to extract the time differences between the two decays, leading to a new evaluation of $^{216}$Po half-life, estimated as <math><mo>(</mo><mn>143.3</mn><mo>±</mo><mn>2.8</mn><mo>)</mo></math> ms.

O. Azzolini

J.W. Beeman

F. Bellini

M. Beretta

M. Biassoni

C. Brofferio

C. Bucci

S. Capelli

L. Cardani

P. Carniti

V. Caracciolo

N. Casali

D. Chiesa

M. Clemenza

I. Colantoni

O. Cremonesi

A. Cruciani

I. Dafinei

A. D'Addabbo

S. Di Domizio

F. Ferroni

L. Gironi

France

A. Giuliani

P. Gorla

C. Gotti

G. Keppel

M. Martinez

S. Nagorny

M. Nastasi

S. Nisi

C. Nones

D. Orlandi

L. Pagnanini

M. Pallavicini

L. Pattavina

M. Pavan

G. Pessina

V. Pettinacci

S. Pirro

S. Pozzi

E. Previtali

A. Puiu

C. Rusconi

K. Schäffner

C. Tomei

M. Vignati

A. Zolotarova

Measurement of Po half-life with the CUPID-0 experiment

Half-lives of the low-lying yrast states of $^{212}$Po have been measured using the delayed coincidence fast-timing method. We report on the first measurement of the <math><msubsup><mrow><mn>4</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math> half-life, as well as a new measurement of the <math><msubsup><mrow><mn>6</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math> half-life with improved accuracy compared to previous studies. The extracted lifetime of the <math><msubsup><mrow><mn>4</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math> and <math><msubsup><mrow><mn>6</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math> state have been determined to be 100(14) ps and 1.66(28) ns respectively. With these measurements, precise values are now available for the reduced transition strengths B(E2) of all ground state band levels in $^{212}$Po up to the first <math><msup><mrow><mn>8</mn></mrow><mrow><mo>+</mo></mrow></msup></math> state, in particular B(E2; <math><msubsup><mrow><mn>4</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msubsup><mo>→</mo><msubsup><mrow><mn>2</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math>) = 9.4(13) W.u. and B(E2;<math><msubsup><mrow><mn>6</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msubsup><mo>→</mo><msubsup><mrow><mn>4</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math>) = 8.7(15) W.u. Comparison of the new available data with an α-clustering model calculation provides evidence that the inclusion of the α-cluster degree of freedom significantly improves agreement with experimental data compared to earlier shell model calculations.